I. Field
The following description relates generally to wireless communication and more particularly to transmitting wireless signals.
II. Background
Communications systems frequently include a plurality of network nodes, which are coupled to access nodes through which end nodes (e.g., mobile devices) are coupled to the network. Network nodes may be arranged in a hierarchy. End nodes typically communicate with access nodes directly through connections that have been established with said access nodes. Such systems usually rely on the existence of a bidirectional communications link between an access node and end node to support two-way communications between an end node and an access node.
In order to communicate effectively network nodes and end nodes transmit communications intended for each other through antennas. Such communication sent through an antenna needs to be transmitted with enough power that it can be heard by the intended recipient. In communication networks that communicate using a simple signal (e.g., Time Division Multiple Access (TDMA) signals), wherein the signals are nearly identical and antennas can include a singe transformer winding. However, when complex signals are involved, such as for Orthogonal Frequency Division Multiplexing (OFDM) systems, a single winding results in a complex structure that must account for a higher peak average ratio developed when the combined signals/tones are amplified. In addition, there is a need to reduce the relative loading effect with such complex signals because there is less randomness of the discrete tones, therefore, any design utilizing a single winding would have to be to a much higher voltage.
Therefore, there is a need for an antenna that can provide the necessary power for complex signals, combine signals for transmission, and minimizing a relative loading effect of the outputs of different tones on the amplifiers used to amplify the tones. In addition, there is a need for a less complex amplifier structure for amplifying the combined signals/tones.